Antimicrobial process on metal

ABSTRACT

An anodized aluminum sheet, which is heat sealed and coated with an antimicrobial composition. The antimicrobial coating may be bound to the surface of the anodic layer and can comprise a network of cross-linked organo-silane molecules that are also covalently bound to the surface of the anodic layer. A process also is provided including: forming an anodic layer on the surface of an aluminum substrate; heat sealing the anodic layer; preheating the sheet; applying an antimicrobial composition at an application rate sufficient for the composition to at least begin binding to the surface of and form an antimicrobial coating over the anodic layer; and post heating the coated anodized antimicrobial sheet to further bind the composition to cure the antimicrobial coating. Optionally, the heat sealed anodic layer can be etched to create a bonding layer to which the antimicrobial composition strongly bonds.

RELATED APPLICATIONS

The present application is related to and claims priority to U.S. Provisional Patent Application, Ser. No. 61/411,541, filed on Nov. 9, 2010, entitled “Antimicrobial Process on Metal.” The subject matter disclosed in that provisional application is hereby expressly incorporated into the present application.

TECHNICAL FIELD AND SUMMARY

The present disclosure relates to a continuous web or sheet of anodized aluminum including an improved coating and a method for manufacturing the same.

Anodized aluminum is used in a variety of architectural applications. For example, due to its corrosion and weather resistance, anodized aluminum sheets are used on building exteriors. Anodized aluminum sheets also are used in interior architectural applications. Interior architectural components, such as walls, back splashes, partitions, door knobs and table tops, can be manufactured from sheets of anodized aluminum.

A problem with anodized aluminum sheets is that the surfaces of the sheets are highly hydrophilic. Therefore, water-born microbes and pathogens frequently become joined with the architectural anodized aluminum sheets. This can become problematic because installed interior architectural sheets are touched or contacted by many different people. In cases where the anodized aluminum sheet is infrequently washed, and where microbes and pathogens are given the opportunity to grow on the surface of the anodized aluminum, the anodized aluminum sheet can become a transfer agent for those microbes and pathogens. This can lead to an unnecessary health hazard.

To overcome such problem, one embodiment of the present disclosure describes an organo-silane based antimicrobial composition for a metal surface. Optionally the organo-silane is 3-(trimethoxysilyl) propyldimethyloctadecyl ammonium chloride.

The present disclosure also provides a method for producing an antimicrobial anodized aluminum product in continuous web or sheet form including: forming an anodic layer on the surface of an aluminum substrate by anodically coating an aluminum core in an electrolyte solution; heat sealing the anodic layer with a heated solution of water; preheating the web or sheet to a range from about 140° F. to about 200° F.; applying an antimicrobial composition at an application rate sufficient for the composition to at least begin binding to the surface of and form an antimicrobial coating over the anodic layer; and post heating the coated anodized antimicrobial web or sheet to a range from about 140° F. to about 200° F. to further bind the composition to cure the antimicrobial coating.

In another embodiment, after heat sealing of the anodic layer, the anodic layer may be etched with an etching composition, to enable the subsequently applied antimicrobial coating to better join with the remaining portion of the anodic layer. The etching composition, optionally in a solution form, may be applied to the web or sheet in a variety of ways, for example: by cascading the etching solution over the web or sheet; by misting the etching solution over the web or sheet; by spraying the etching solution on the web or sheet; by dipping the web or sheet in the etching solution; and/or by rolling or brushing the etching solution on the web or sheet. Further optionally, heat or temperature regulated air flow may be applied on the web or sheet to affect the etching process.

The present disclosure provides a continuous web or sheet of anodized aluminum including an antimicrobial coating that inhibits or prevents the growth of microbes such as bacteria, mold, mildew, algae, fungi, and yeast. When the continuous web or sheet is used to manufacture architectural materials and/or components that are frequently contacted by various users, it can reduce the spread of microbes, particularly pathogenic microbes, among those users.

Additional features and advantages of the antimicrobial process will become apparent to those skilled in the art upon consideration of the following detailed descriptions exemplifying the best mode of carrying out the antimicrobial process as presently perceived.

BRIEF DESCRIPTION OF DRAWINGS

The present disclosure will be described hereafter with reference to the attached drawings which are given as non-limiting examples only, in which:

FIG. 1 is a schematic view of a process for manufacturing an antimicrobial anodized aluminum continuous web according to and embodiment of the present disclosure;

FIG. 2 is a diagram of an antimicrobial composition suitable for use with the present disclosure;

FIG. 3 is a diagram of the antimicrobial composition in another form;

FIG. 4 is a view of the antimicrobial composition bound to an anodic layer of a continuous web of anodized aluminum; and

FIG. 5 is a schematic view of another process showing a pre-anodized coil product having an antimicrobial composition applied using secondary application equipment.

DISCLOSURE OF ILLUSTRATIVE EMBODIMENTS I. Construction

The antimicrobial anodized aluminum product of the present disclosure includes a continuous web (e.g., a substantial length of aluminum that can be pulled through multiple processing stations) or sheet having an anodic layer on one or both sides of the web or sheet.

Illustratively, to produce the anodic layer, a continuous web of raw aluminum core 70 is provided and subjected to an electrolytic solution and anodizing environment. A variety of acids, such as sulfuric acid, oxalic acid, chromic acid, organic acid and/or phosphoric acid, may be used to form the anodic layer. The thickness of the anodic layer after anodizing can be about 0 mils to about 0.400 mils, and preferably about 0.175 mils.

The anodic coating (aluminum oxide or Al₂O₃) layer 50 is formed during anodizing is porous. There are narrow holes in the aluminum oxide layer that are about 100 angstroms in diameter that extend from the top of a pore to the bottom of the pore. When the web including the anodic coating is placed in a bath of boiling water (e.g., in the sealing station 6), water absorbs the aluminum oxide, which in turn swells the aluminum oxide layer, substantially closing the pores. There also is a chemical reaction between the aluminum oxide and water, such that Al₂O₃+H2O form a structure, 2*A10(OH), which is called Bomite. The part of the aluminum oxide that has been converted to Bomite has less density than the part of the aluminum oxide layer that has not been hydrated by the water.

The antimicrobial composition joined with the anodized layer can be a metal, such as silver, copper, and/or zinc that is coated and bound to the anodic layer. Other suitable antimicrobial compositions are organo-silanes. A suitable organo-silane, which is water based, is 3-(trimethoxysilyl) propyldimethyl-octadecyl ammonium chloride), which is commercially available from Nova BioGenetics, Inc., of Atlanta, Ga., under the trade name BST AM500, and also commercially available from Aegis Environments of Midland, Mich., under the trade name Aegis Microbe Shield® AEM 5772 or AEM 5700. Organo-silanes that are similar in composition to those available through Nova BioGenetics and Aegis can also be used. The empirical formula for this compound is C₂₆H₅₈C1 N 03 Si, and the molecular weight is 496.29. The structure of this organo-silane, shown as an active ingredient in a dilute aqueous solution, such as water or methanol, is illustrated in FIG. 2. The structure of this organo-silane, shown as an active ingredient in a concentrate, is illustrated in FIG. 3.

With reference to FIG. 2, the organo-silane includes both a cross-linking or binding head 20 and a microbe inhibiting/destroying tail 30. The tail 30 is capable of inhibiting/destroying a variety of microbes, for example, bacteria, such as Escherichia coli and Staphylococcus aureus, as well as mold, mildew, algae, fungi, and yeast.

The organo-silane of the present disclosure is used to form a coating on the treated anodic layer 60 of the continuous web or sheet of anodized aluminum. Specifically, with reference to FIG. 4, the organo-silane head 20 performs two functions. In one, it attaches the surface of the treated anodic layer 60 via short range Van der Waals and/or hydrogen bonding forces. In another, the head of one organo-silane molecule (a silanol group) reacts with another silanol group of an adjacent organo-silane molecule and cross-links with it.

When applied to the treated anodic layer 60 in mass quantity, multiple organo-silane silanol groups react and bind together to the anodic layer 60. Where other hydroxyl, amine, or other substrate groups are present, the organo-silane molecule can join directly with those molecules or substrates as well. After the head 20 of each molecule binds to the anodic coating, the antimicrobial head 30 remains exposed to form a nanocoating of the organo-silane antimicrobial on the surface of the anodic layer. This antimicrobial nanocoating can be of a depth from about 10 micrometers to about 40 micrometers, and preferably about 20 micrometers.

II. Method of Manufacture

A method for producing an antimicrobial anodized aluminum product in continuous web or sheet form will now be descried with reference to FIGS. 1 and 4. With reference to FIG. 1, a continuous raw aluminum or aluminum alloy core web is introduced to the anodizing station 4 where it is anodicly polarized in an electrolyte solution to form the anodic layer. The web 2 continues to station 6 where it is heat sealed in a solution of hot water at a temperature of about 205° F.

After the continuous web 2 is heat sealed, it continues to preheating station 8. At this station, the web is heat treated to a range from about 140° F. to about 200° F., preferably about 180° F. Before this heat treatment, the temperature of the web is about 115° F. The heaters are stationed about 4 inches to about 10 inches from the web, preferably about 6 inches from the web, to exert the appropriate amount of heat to elevate the temperature of the surface of the web to the aforementioned ranges. A suitable heater is a Chromalox® S-RAD single element radiant heater, which is available from Chromalox, Inc. of Pittsburgh, Pa. Although shown with heaters on both sides of the web, one set of heaters (opposite the misted side of the web) optionally can be deleted from stations 5 and 8.

After the web 2 is preheated, it continues on to pass the misters 7, which mist a coating of antimicrobial composition onto the surface of the anodic layer of the web 2 on one side of the web. Optionally, both sides of the web may be misted as the application requires. The web passes the misters at a speed from about 10 feet per minute to about 50 feet per minute including about 25 feet per minute. The misters can be spaced about 3 inches to about 10 including about 7 inches, away from the web. The misters can also be spaced about 6 inches to about 10 inches from one another (beside one another, across the web), and preferably about 8 inches from one another.

The antimicrobial composition supplied through the mister can include the organo-silane described above. That organo-silane can be diluted before being applied by the misters. Specifically, the mixture of the antimicrobial composition may be about 1% to about 10%, or about 1.5% to about 2.5%, 3.4% to 6.8% or about 6.8% by volume Aegis AEM 5700; about 0.001% to about 2%, preferably about 0.1% by volume Dow Coming Q2-5211 Superwetting Agent (commercially available from Dow Corning Corporation of Midland, Mich.); and about 90% to about 99%, preferably about 93.1% high purity reverse osmosis (RO) water.

The reverse composition can be applied through the misters at about 4 psi with an application from about 0.1 milliliters to about 0.8 milliliters, preferably about 0.3 milliliters, per nozzle per square foot of the continuous web 2. The total application rate for all the nozzles on the continuous web is a range from about 1.5 milliliters to about 2.5 milliliters per square foot of the web. As noted above, when the antimicrobial composition is organo-silane and it is applied to the surface of the web, it hydrogen bonds to the surface of the anodic layer, and the heads of the organo-silane cross-link to one another. FIG. 4 illustrates on a molecular level the interaction of the organo-silane molecules with one another and the anodic layer to form an antimicrobial nanocoating on the anodic layer.

After the antimicrobial composition is sprayed to one side of the web, the continuous web 2 passes a first post-heating station 5. This station can apply heat to the web to keep the temperature of the web an elevated range from about 140° F. to about 200° F., preferably about 180° F. At or near this station, the aqueous carrier, for example the water and methanol, begins to evaporate. Depending on the application rate, a third post-treatment heater 3 can be included in the system to further evaporate the water from the web and/or other volatile carriers from the antimicrobial composition.

The continuous web, now coated with an antimicrobial coating as described above, can be processed using conventional techniques, and rolled or cut for further distribution.

EXAMPLE 1

An example of preparing an antimicrobial composition and applying it to a continuous web of anodized aluminum will now be described.

An antimicrobial composition was prepared by adding 1285 milliliters of the organo-silane Aegis AEM 5700 to an aqueous carrier having 17696 milliliters of RO water and 19 milliliters of Dow Corning Q2-5211 Superwetting agent to produce the resulting antimicrobial composition. The resulting antimicrobial composition was placed in liquid communication with the mister station 7.

Next, a continuous web 2 was anodized and heat sealed. The surfaces of the web 2 were heated to approximately 180° F. at preheating station 8. The anodized web 2 was fed past the antimicrobial treatment station 7 at a rate of about 25 feet per minute. The misters applied 2 milliliters per square foot of the antimicrobial solution to the passing web 2. The passing web was subjected to a post-heating at station 5 where the web was heated again to about 180° F., where substantially all of the water and methanol were evaporated off the web 2, and substantially all of the organo-silane remained to form an antimicrobial nanocoating over the anodic layer 60. Further post-treatment heating was performed at station 3.

A sample of the completed web 2 was then tested for its antimicrobial properties. Specifically, the sample was subjected to JIS 2801-2000: Static Surface contact: Japanese Industrial Standard: Antimicrobial products Test for antimicrobial activity and efficacy and ASTM E2149-01, “Standard Test Method for Determining the Antimicrobial Activity of Immobilized Antimicrobial Agents Under Dynamic Contact Conditions,” ASTM International, which are hereby incorporated by reference. The results of the test on the sample produced in this example indicated a 99.99% reduction in staphlococcus aureus, which indicated that the antimicrobial anodized aluminum product of the present disclosure had exceptional antimicrobial properties.

III. First Alternative Embodiment

An alternative embodiment of the present disclosure will now be described. In this alternative embodiment, after the continuous web 2 is heat sealed and before it continues to preheating station 8, it is subjected to an etching composition that lightly etches the sealed, anodic layer. “Etching” is a chemical treatment whereby an etching composition is applied to and partially or fully dissolves or removes a sealed layer or an anodic film or layer on an anodized aluminum surface to create a roughened morphology. An “etching composition” can be any alkaline or acidic media capable of dissolving or removing all or a portion of aluminum oxide to a substantial degree, including but not limited to sodium hydroxide, calcium hydroxide, phosphoric acid, hydrofluoric acid, sulfuric acid, bromic acid, and chromic acid.

A “roughened morphology” refers to a condition where the heat sealed layer or anodic film of the anodized aluminum includes an extended or protruded surface area, which provides many sites for an increased number of mechanical, and in some cases, chemical-bonds between the heat sealed layer or the anodic layer and an antimicrobial composition applied over the heat sealed layer and/ or anodic film. The roughened morphology may resemble the surfaces depicted in FIGS. 1 and 2, or other configurations depending on the etching solution applied, the duration of application, and the temperature.

The etching composition may be a solution of water or other suitable liquid mixed with an alkaline, acidic, or other caustic material capable of dissolving and/or removing the heat sealed layer and/or aluminum oxide layer. One etching solution is a solution of sodium hydroxide from about 0.1 to about 0.5 molar. Optionally, sodium hydroxide solutions, from about 0.5 to about 1.5 molar and 1.0 to about 4 molar, may also be used. Alternatively, the etching solution may be a solution of phosphoric acid in concentrations of optionally about 0.1 to about 5.1 molar, further preferably about 0.5 to about 3.0 molar, and even further preferably about 0.75 to about 1.5 molar. Solutions of sulfuric acid may also be used, however, the temperature and duration of time required to sufficiently dissolve an aluminum oxide layer must be significantly increased relative to the temperature and duration required with sodium hydroxide solutions and phosphoric acid solutions.

The pre-etched heat sealed layer and anodic layer can be greater than 0.1 mils (thousandths of an inch) or about 2.54 microns in depth. Due to the etching, at least a portion of the heat sealed layer and the anodic layer are removed so that a newly created bonding layer remains where that bonding layer includes a roughened morphology. In this morphology, the bonding layer may be about 1 to about 20 nanometers, preferably 2 to about 10 nanometers, and most preferably about 5 to about 6 nanometers in depth. Of course, the bonding layer can be of lesser proportions as desired, for example, only 5%, 10%, 20%, 30%, and/or 40% of the above noted depths, depending on the desired bonding of the antimicrobial composition to the remaining portion of the heat sealed and/or anodic layers. Other roughened morphologies that increase the potential for mechanical interlocking of the antimicrobial composition to the heat sealed and/or anodic layer can be used as desired, for example, those explained in U.S. Pat. No. 7,029,597 to Marzak, filed Jul. 5, 2001, which is hereby incorporated by reference in its entirety.

After the etching composition is applied to the web or sheet and the desired bonding layer created, the web or sheet can be pre-heated at station 8 and processed as set forth in the embodiment above to apply the antimicrobial composition as desired.

EXAMPLE 2

Another example of preparing an antimicrobial composition and applying it to a continuous web of anodized aluminum will now be described.

An antimicrobial composition was prepared by adding 136 milliliters of the organo-silane Aegis AEM 5700 to an aqueous carrier having 1864 milliliters of RO water to produce the resulting antimicrobial composition. The resulting antimicrobial solution was placed in and allowed to hydrolyze for one hour, and was heated to 210° F. before samples were immersed in the solution.

A web of aluminum was anodized and heat sealed. Thereafter, the web was etched to remove at least a portion of the heat sealed layer and the anodic layer of the web. The etching was performed with a solution of 0.15 M molar sodium hydroxide, at a temperature of about 80° F., rolled onto the web, and left in contact with the web for about 2 seconds before the solution was rinsed from the web. It is believed that the etching composition created a bonding layer of about 2 microns. Thereafter, one 4 inch×6 inch sample was removed from the web.

The sample was individually immersed in the antimicrobial solution for about five minutes. Then the sample was rinsed with RO water and air dried. It is believed that substantially all of the organo-silane remained to form an antimicrobial nanocoating over the bonding layer. Further, it is believed that this nanocoating should be sufficiently bonded to the bonding layer so that the resulting sample can withstand further processing, such as stamping, bending, and other physical modification, without the antimicrobial nanocoating flaking off from, or otherwise disengaging, the sample to preserve the antimicrobial properties of the sample.

IV. Second Alternative Embodiment

Various other processing techniques are being tested to produce a bonding layer to which the antimicrobial composition can join and remain joined upon further physical modification of the web or sheet. Several of these processing techniques are described below. In the first four techniques, an antimicrobial composition was prepared by adding 136 milliliters of the organo-silane Aegis AEM 5700 to an aqueous carrier having 1864 milliliters of RO water to produce the resulting antimicrobial composition. The resulting antimicrobial solution was allowed to hydrolyze for one hour and was heated to 210° F. before samples were immersed in the solution.

In the first technique, two samples of raw ClearMatt, available from Lorin Industries of Muskegon, Mich., and two samples of Alumaplus raw metal, also available from Lorin Industries, were cleaned with phosphoric acid at a concentration of 4.5% for one minute each, then rinsed with RO water. Next, the samples were caustic etched with sodium hydroxide at a concentration of 38 g/l for one minute each, then rinsed with RO water, and then dipped in the antimicrobial solution for five minutes to coat the surfaces of the samples with an antimicrobial coating.

In the second technique, two samples of ClearMatt, available from Lorin Industries, were cleaned for one minute, rinsed, caustic etched with sodium hydroxide at a concentration of 38 g/l for one minute, rinsed again, desmutted with nitric acid at a concentration of 8% for 15 seconds, anodized for 2.5 minutes with 12 amps, rinsed yet again, and dried. The samples were then dipped in the antimicrobial solution for five minutes to coat the surfaces of the samples with an antimicrobial coating.

In the third technique, two samples of ClearMatt were cleaned, immersed in phosphoric acid at a concentration of 30% for four minutes. The samples were then dipped in the antimicrobial solution for five minutes to coat the surfaces of the samples with an antimicrobial coating. Two Alumaplus raw metal finish samples were also processed using the same techniques.

In the fourth technique, two samples of Alumaplus, available from Lorin Industries, were anodized after being cleaned for one minute in phosphoric acid at a concentration of 4.5% and bright dipped in nitric acid at a concentration of 3.5% for one minute. Then the samples were dipped in the Alumaplus dye tank, which includes Grey NLN from Specialty Dye and Bronze 2LW from Clariant, at a concentration of 0.8 g/l and 0.25 g/l, respectively, for one minute, then sealed with nickel and hot water. Two more samples followed the same processing steps, except for the sealing process of nickel and hot water. Four Clearmatt samples, available from Lorin Industries, were also processed in the same order. Two of these Clearmatt samples were sealed and two of them were not.

In a fifth technique, 1360 milliliters of AEM 5700 were added to a 20-liter dye tank, which already included a dye solution having 16 grams of Grey NLN dye and 5 grams of Bronze 2LW with the remaining volume being water. Two anodized samples were passed from the anodizing tank to the dye tank, which included the Aegis chemistry. Then the samples were immersed into the nickel seal for one minute and the hot water seal for five minutes.

In another embodiment a continuous web or sheet of pre-anodized aluminum 40 is processed from a payoff spool 42 to a rewind spool 44, as shown for example, in FIG. 5. During this process, the web of aluminum 40 is first heated by heaters at station 46 to a range from about 140° F. to about 200° F., preferably to about 180° F. The heaters are stationed about 8 inches to about 16 inches from the web, preferably about 12 inches from the web.

After the web 40 is preheated, the web is passed under the application point 48. Application may include up to two Nordson Rotary Atomizer guns applying antimicrobial solution at a rate from about 1 oz/min to about 4 oz/min. The web 40 passes the application point 48 at a speed from about 7 feet/min to about 90 feet/min, preferably at about 25 feet/min. The web 40 is next heated by a second set of heaters at station 58. This station can apply heat to the web 40 to keep the temperature of the web 40 an elevated range from about 140° F. to about 200° F., preferably about 180° F. The heaters are stationed about 8 inches to about 16 inches from the web, preferably about 12 inches from the web. At or near this station, the aqueous carrier, for example the water and methanol of the solution, begins to evaporate.

V. Additional Embodiments

Another illustrative embodiment includes applying AEGIS at concentrations less than 30 mg/square foot. For example, it is contemplated to test: 25 mg/square feet, 20 mg/square feet, 15 mg/square feet, and 10 mg/square feet. Previously, tests were conducted using an AEGIS concentration in the range of 30 mg/square foot to 125 mg/square foot. These tests showed little to no difference in the Anti-microbial performance in this concentration range. Testing lower concentrations may determine the minimum amount of AEGIS needed to be effective. Samples can be made and tested to determine the effectiveness of their coatings. In addition, the samples can be subjected to a washability test at 100 cycles using a mild abrasive cleaner such as Soft Scrub® with bleach available from the Dial Corporation to compare the durability of the coating to past work. Illustratively, a plurality of samples, such as 4 samples, can be subjected to the washability test, and 8 samples can be subjected to bacteria testing (4 coated, 4 coated and washed).

Another illustrative embodiment includes determining minimum cure times for the AEGIS coating. Current recommendations suggest the coating be cured at about 100 degrees C. for about 30 minutes, or about 14 days at about room temperature. Per such recommendations a full scale production line would need to include a long enough oven to get the 30 minute cure time at a reasonable line speed. For example, based on a calculation of X feet per minute (FPM) of line speed times a 30 minute cure time equals the length of the oven, if X is 7 FPM, a 210 foot length of oven is needed. If running 90 FPM, a 2,700 foot long oven is needed. Accordingly, determining a minimum cure time less than 30 minutes may be useful. An illustrative contemplated testing protocol to reduce the time includes coating a plurality of 16″×16″ samples. Then cure the samples in the oven at different temperatures and times. The samples may be tested using a blue dye test to determine when the coating is cured. An exemplary substrate to test is anodized aluminum at temperatures of 212°/100° C., 225° F./107° C., 250° F./121° C., 275° F./135° C., and 300° F./148° C. for the following cure times: i) 5 minutes, ii) 10 minutes, iii) 15 minutes, iv) 20 minutes, v) 25 minutes, and vi) 30 minutes. Once the samples are cured, they can be tested immediately using the blue dye test. Uncured samples will show the coating as uneven or not on the metal. Cured samples should show an even blue color across the sample. Once a minimum cure time is determined, more samples can be tested using heat sensitive tape applied to the sheet. This may determine the maximum temperature the sheet reaches in the oven during the cure process. For example, about 31 samples (1 non-coated, 30 coated and cured) could be tested for color and gloss; 30 samples could be tested for blue dye test; and 32 samples could be tested for bacteria (30 coated, 2 uncoated control).

The above descriptions are those of the preferred embodiments of the disclosure. Various alterations and changes can be made without departing from the spirit and broader aspects of the disclosure as defined in the appended claims, which are to be interpreted in accordance with the principles of patent law including the doctrine of equivalents. Any references to claim elements in the singular, for example, using the articles “a,” “an,” “the,” or “said,” is not to be construed as limiting the element to the singular. Any reference to “at least one of X, Y and Z” refers to one or more of X, Y, or Z, but does not require that each of X, Y and Z be present.

Corresponding reference characters indicate corresponding parts throughout the several views. The exemplification set out herein illustrates an embodiment of the invention in one form, and such exemplification is not to be construed as limiting the scope of the invention in any manner.

Although the present disclosure has been described with reference to particular means, materials and embodiments, from the foregoing description, one skilled in the art can easily ascertain the essential characteristics of the invention and various changes and modifications may be made to adapt the various uses and characteristics without departing from the spirit and scope of the invention. 

1. A method of producing a continuous web of anodized antimicrobial aluminum comprising: creating an anodic layer on the surface of an aluminum web in an electrolytic solution; heat sealing the anodic layer to produce a heat seal layer adjacent the anodic layer; preheating the heat sealed web from about 140° F. to about 200° F.; misting an organo-silane composition on the heat sealed anodic layer so that the organo-silane binds to the pores of the anodic layer; reheating for a first time the web from about 140° F. to about 200° F. to enhance cross-linking of adjacent organo-silane molecules and the formation of a nanocoating on the surface of the anodic layer; and reheating for a second time the web from about 140° F. to about 200° F.
 2. The method of claim 1 comprising applying an etching composition to the heat sealed web to remove at least a portion of at least one of the heat sealed layers and the anodic layer, so that a remaining portion of at least one of the heat sealed layers and the anodic layer is transformed to attain a roughened morphology which improves the binding of the organo-silane to the remaining portion of the at least one of the heat sealed layers and the anodic layer.
 3. The method in accordance with claim 1, wherein the organo-silane composition is mixed with a solvent or diluent prior to misting.
 4. The method in accordance with claim 1, wherein the organo-silane composition has a cross-linking head and a microbe inhibiting tail.
 5. The method in accordance with claim 1, wherein the nanocoating on the surface of the anodic layer has a depth from about 10 micrometers to about 40 micrometers.
 6. The method in accordance with claim 1, wherein heaters are used to preheat the aluminum web and are spaced from about 3 inches to about 10 inches from the aluminum web.
 7. The method in accordance with claim 3, wherein the organo-silane composition includes from about 0.001% to about 2% wetting agent.
 8. The method in accordance with claim 7, wherein the organo-silane composition includes from about 90% to about 99% high purity reverse osmosis water.
 9. The method in accordance with claim 1, wherein the organo-silane is applied through misters at about 4 psi with an application from about 0.1 milliliters to about 0.8 milliliters per nozzle per square foot of the continuous web.
 10. A method for producing a web of anodized antimicrobial aluminum comprising: placing a web of anodized aluminum onto a payoff spool; connecting a first end of the web of anodized aluminum to a rewind spool; heating the web of anodized aluminum from about 140° F. to about 200° F.; applying an organo-silane composition on the heated web of anodized aluminum so that the organo-silane binds to the pores of the aluminum; and reheating the web from about 140° F. to about 200° F. to enhance cross-linking of adjacent organo-silane molecules and the formation of a nanocoating on the surface of the aluminum.
 11. The method in accordance with claim 10, wherein the organo-silane composition is applied at a rate from about 1 oz/min to about 4 oz/min.
 12. The method in accordance with claim 11, wherein the web passes the application point at a speed from about 7 feet/min to about 90 feet/min.
 13. The method in accordance with claim 10, wherein the organo-silane composition is mixed with a solvent or diluent prior to misting.
 14. The method in accordance with claim 10, wherein the organo-silane composition has a cross-linking head and a microbe inhibiting tail when bound to the aluminum.
 15. The method in accordance with claim 10, wherein the nanocoating on the surface of the aluminum has a depth from about 10 micrometers to about 40 micrometers.
 16. The method in accordance with claim 10, wherein heaters are used to preheat the aluminum web and are spaced from about 8 inches to about 16 inches from the aluminum web.
 17. The method in accordance with claim 13, wherein the organo-silane composition includes from about 0.001% to about 2% wetting agent.
 18. The method of claim 10 comprising applying an etching composition to the aluminum sealed web prior to applying the organo-silane composition to attain a roughened morphology to improve the binding of the organo-silane to the remaining portion of the aluminum web.
 19. A method for producing an anodized antimicrobial aluminum comprising: creating an anodic layer on the surface of aluminum in an electrolytic solution; heat sealing the anodic layer to produce a heat seal layer adjacent the anodic layer; preheating the heat sealed aluminum from about 140° F. to about 200° F.; misting an organo-silane composition on the heat sealed anodic layer so that the organo-silane binds to the pores of the anodic layer; and reheating the aluminum from about 140° F. to about 200° F. to enhance cross-linking of adjacent organo-silane molecules and the formation of a nanocoating on the surface of the anodic layer.
 20. An anodized antimicrobial aluminum adapted to resist the formation of microbes on the surface of the aluminum comprising: an anodic layer positioned near a surface of the aluminum; a heat sealed anodic layer positioned to lie near the anodic layer; organo-silane molecules bound to the surface of the heat sealed anodic layer wherein the organo-silane molecules are cross-linked with adjacent organo-silane molecules to form an antimicrobial coating. 